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J. G. COREY. Anima1Shears.

Patented-July 13, 1880'.

UNITED STATES PATENT OFFICE.

JOHN G. COREY, OF SANTA PAULA, ASSIGNOR OF ONE-HALF OF HIS RIGHT TO NATHAN l/V. SPAULDING, OF SAN FRANCISCO, CALIFORNIA.

ANIMAL-SH EARS.-

SPECIFIGATION forming part of Letters Patent No. 229,872, dated July 13, 1880.

' Application filed December 4, 1879.

To all whom it may concern:

Be it known that I, JOHN G. COREY, of Santa Paula, county of Ventura, and State of California, have invented an Improvement in Sheep-Shears; and I hereby declare the following to' be a full, clear, and exact description thereof.

My invention relates to certain. improvements in sheep-shears; and it consists in a IO novel means for adjusting the tension of the spring, so that any pair of shears may be adjusted from the lightest to the heaviest tension to suit the hand of the operator, and to regulate them so as to be used in light, heavy, or

dirty wool, as will be more fully described by reference to the accompanying drawing, in which the figure is a view of one form of sheepshears having my improvement attached.

Great difficulty is experienced by operators 29 in selecting a pair of shears in which the tension of the spring is such as to exactly suit the hand, and they will often try all the stock of the dealer without finding a pair to suit. It is also necessary to employ shears having 2 5 a spring of greater or less tension, as the wool may be heavy, dirty, or light; and, finally, the hand of the operator, which is strong in ,the morning, will become weak after a days work is nearly finished, and he must use a lighter 30 pair of shears, or rather with less tension.

My invention is designed to so adjust the tension of the spring that a single pair of shears will meet all the requirements of the shearer; and it consists in the employment of 3 5 a movable fulcrum, which may be fixed at any point between the sides of a U or other spring having parallel sides, so that by moving this fulcrum from one end to the other of the spring the tension may be changed from the lightest 4 to the heaviest that may be desired.

In the present case I have shown my invention as applied to the bow-spring shears; but it will be seen that it may be equally well employed in connection with other forms and with the same results.

A A are the blades of a pair of shears, and B is the connecting {curved or bow spring which unites the rear ends of the shanks C. The strength of this spring determines the ten- 5 sion or stiffness of the shears, and this is always unalterable, except by grinding the spring down.

In my invention I secure a curved or U- shaped spring, D, between the shanks. The ends of this spring are bent outward, so that they may be riveted or otherwise secured to the inside of the shanks. Thebight or curve E of the spring which unites the parallel sides D is carried back into the bow B, as shown.

Between the parallel sides D of the spring I place a fulcrum, F, which may be moved from the curve E to the opposite end and fixed at any desired point.

When the blades of .the shears are closed the sides of the spring D will be moved toward each other, and when the fulcrum is not between them the rear curve, E, is the point about which they move. It will be seen that as the fulcrum is advanced from this curve toward the front its tendency is to prevent the sides of the spring from approaching, except in front of the fulcrum, and the more it is advanced the stiffer the spring becomes. This fulcrum may be formed in different ways; but

the simplest and most eflicient is to make a short coil of spring-wire, of a diameter just sufficient to fill the space between the sides D of the spring. The ends of this wire are bent,

as shown at G, so as to clasp one of the sides D, and the elasticity of the coil will cause the fulcrum to cling to or clasp the spring, so that it will remain at anypoint where it may be set, and it can be easily moved by the thumb and finger to any desired point. By moving it entirely out of the space between the sides D and up on the outwardly-curving portion of the spring it will cease to act as a fulcrum, and the tension of the shears will then be just what is due to the curves B and E of the two springs. This tension should be the weakest 0 which will be needed, and it can be increased to any desired stiffness.

The gripe of the hand and the friction of the fulcrum'upon the two parts of the spring will prevent any tendency which the shear-blades 9 5 might have to slip by each other in heavy or dirty wool, technically called buckling.

My device may be equally well applied to shears the blades of which are united by a rivet through the ends of the shanks, it being only necessary to introduce the spring D and the movable fulcrum, as before described.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The blades A, with their shanks O, united at the rear end as a fulcrum, in combination with the spring 1), having its ends secured to the shanks O, and having a fulcrum, F, fitted 10 to move between its parallel sides, whereby the tension of the shears is-adj usted, substantially as herein described.

2. The shear-blades A, with their shanks united at the rear end, and the spring D, having its ends secured to the shanks, as shown, 15 in combination with the coiled elastic spring F, with its clasping ends G, said spring forming an adjustable fulcrum, substantially as and for the purpose herein described.

In witness whereof I have hereunto set my 20 hand.

JOHN GRIFFITH COREY.

Witnesses:

H. H. DOBBINS, L. SKINNER. 

